Actively exploited in the wild
Joomlack Page Builder Improper Access Control Vulnerability
Joomlack - Page Builder · Listed in the CISA KEV since 2026-07-07. This indicates confirmed attacks in production environments.
Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
CVE-2026-56290
CriticalCVSS 9.8KEVExploitation Probability (EPSS)
Very high risk100th percentile - higher than 100% of all known CVEs
Summary
The Page Builder CK extension for Joomla versions below 3.6.0 contains a vulnerability allowing an unauthenticated attacker to upload arbitrary files, including executable files. This leads to full remote code execution (RCE).
Risk Assessment
An attacker can fully compromise the Joomla server, gaining access to data and the ability to further attack the infrastructure.
Recommendation
Immediately update the Page Builder CK extension to version 3.6.0 or later.
Original NVD description (English source)
Joomla Extension - joomlack.fr - Unauthenticated file upload in Page Builder CK extension < 3.6.0 - The Joomla extension Page Builder CK is vulnerable to an unauthenticated arbitrary file upload that allows uploading executable files and leads to full RCE.